1. Technical Field
The present disclosure relates to a mold for an optical plate and a manufacturing method thereof, and more particularly to a mold for an optical plate with reduced defects and a manufacturing method thereof.
2. Discussion of the Related Art
An injection molding apparatus is employed to manufacture a desired-shaped injection product from a mixture of a molding material, such as thermoplastic resin, and various additives of a melting state in a molding space formed by a mold or a core.
The injection molding apparatus comprises a first core, a second core, a runner, a gate, and at least one flow channel. The second core moves up and down with respect to the first core and forms a molding space along with the first core. The runner and the gate are disposed between the first core and the second core and inject a molding material to the molding space. The at least one flow channel is provided in each of the first core and the second core. The first core and the second core cooperate to form a shape of the injection product.
The injection product formed by the first and second cores to have a predetermined shape is solidified by cooling water through the flow channel, and then ejected from the first and second cores.
A light guiding plate and a diffusing plate used for a liquid crystal display (LCD) are manufactured by the injection molding apparatus. The light guiding plate guides light from a light source to an LCD panel and may comprise bubbles scattered therein. The bubbles are formed by injecting gas into the molding material. The light passing through the light guiding plate is uniformly diffused to the LCD panel by the bubbles.
However, traces of a flow may be formed on a surface of the light guiding plate due to the gas used for generating the bubbles, and the bubbles may not be disposed in the light guiding plate but be exposed to a surface to cause outward defects of the light guiding plate.